The term “coffee bean” collectively refers to the seeds (coffee seeds) that are obtained by the refining process of removing the pulp and the skin from the berries (known as coffee berries or coffee cherries) of Coffea plants, and the beans that are produced from these. Coffee berries, which contain the coffee bean, are produced by several species of small evergreen plants of the genus Coffea, which are of the family Rubiaceae. The two most commonly grown species are Coffea robusta (also known as Coffea canephora) and Coffea arabica. These are typically cultivated in Latin America, Southeast Asia, and Africa. “Green” coffee beans are coffee beans that have not yet passed through a roasting process, such as the roasting process used in the production of coffee.
The various steps in the production of coffee are described in Smith, A. W., in Coffee; Volume 1: Chemistry pp 1-41, Clark, R. J. and Macrea, R. eds, Elsevier Applied Science London and New York, 1985; Clarke, R. J., in Coffee: Botany, Biochemistry, and Production of Beans and Beverage, pp 230-250 and pp 375-393; and Clifford, M. N. and Willson, K. C. eds, Croom Helm Ltd, London, as described in U.S. patent application Ser. No. 12/941,557 titled Modulation Of Coffee Flavour Precursor Levels In Green Coffee Grains, filed Nov. 8, 2010 on behalf of McCarthy, et al., and published on May 26, 2011 as publication number U.S. 2011/0126314 A1 (hereafter “McCarthy”), the entirety of which is incorporated herein by reference as though set forth in full herein. The process typically starts with the collection of mature, ripe red coffee cherries. The outer layer, or pericarp, can then be removed using either the dry or wet process. The dry process is the simplest and involves: (1) classification and washing of the cherries; (2) drying the cherries after grading (either air drying or mechanical drying); and (3) dehusking the dried cherries to remove the dried pericarp. The wet process is slightly more complicated, and generally leads to the production of higher quality green beans. The wet process is more often associated with C. arabica cherries. The wet process may comprise: (A) classification of the cherries; (B) pulping of the cherries (this step is done soon after harvest and generally involves mechanical removal of the “pulp”, or pericarp, of the mature cherries); (C) “fermentation,” where the mucilage that remains attached to the grain of the cherries after pulping is removed by allowing the grain plus attached mucilage to be incubated with water in tanks using a batch process. The “fermentation” process is allowed to continue up to 80 hours, although often 24 hours is generally enough to allow an acceptable fermentation and to cause the pH to drop from around 6.8-6.9 to 4.2-4.6, due to various enzymatic activities and the metabolic action of microorganisms which grow during the fermentation. The next steps, (D) drying, involves either air or mechanical hot air drying of the fermented coffee grain, and (E) “hulling,” involves the mechanical removal of the “parch” of the dried coffee grain (dried parchment coffee) and often the silverskin. After wet or dry processing, the resulting green coffee grain are often sorted, with most sorting procedures being based on grain size and/or shape.
The next step in the production of conventional coffee is the roasting of the green grain after dehusking or dehulling of dry or wet processed coffee, respectively. This is a time-dependent process which induces significant chemical changes in the bean. The first phase of roasting occurs when the supplied heat drives out the remaining water in the grain. When the bulk of the water is gone, roasting proper starts as the temperature rises towards 374-392 degrees Fahrenheit. The degree of roasting, which is usually monitored by the color development of the beans, plays a major role in determining the flavor characteristics of the final beverage product. Thus, the time and temperature of the roasting are tightly controlled in order to achieve the desired coffee flavor profile. After roasting, the coffee is ground to facilitate extraction during the production of the coffee beverage or coffee extracts (the latter to be used to produce instant coffee products). Again, the type of grinding can influence the final characteristics of the product, such as the flavor of the beverage.
While a considerable amount of research has been carried out on the identification of the flavor molecules in coffee, much less work has been done regarding the physical and chemical reactions that occur within the coffee grains during each of the processing steps. This latter point is particularly evident for the roasting reaction, where the large number of grain constituents undergo an extremely complex series of heat induced reactions (Homma, S. 2001, In “Coffee: Recent Developments”. R. J. Clarke and O. G. Vitzthum eds, Blackwell Science, London; Yeretzian, C., et al ((2002) Eur. Food Res. Technol. 214, 92-104; Flament, I (2002) Coffee Flavor Chemistry, John Wiley and Sons, UK; Reineccius, G. A., “The Maillard Reaction and Coffee Flavor” Conference Proceedings of ASIC, 16th Colloque, Kyoto, Japan 1995).
While the details of most of the reactions that occur during the different steps of coffee processing remain relatively unclear, it is understood that the conventional roasting process likely destroys or degrades many beneficial components present in green coffee beans, including phytonutrients such as, for example, Chlorogenic acid. Chlorogenic acids (CGA) are a family of esters formed between certain hydroxycinnamic acids (i.e. caffeic and feluric acids) and (−)-quinic acid. Green (or raw) coffee is a major source of CGA in nature (5-12 g/100 g) (Farah et al. Braz J Plant Physiol. 365 2006; 18:23-36). The major CGA in green coffee are 3-, 4- and 5-caffeoylquinic acids (3-, 4- and 5-CQA), 3,4-, 3,5- and 4,5-dicaffeoylquinic acids (3,4-, 3,5-, and 4,5-diCQA); 3-, 4- and 5-feruloylquinic acids (3-, 4- and 5-FQA) and 3-, 4- and 5-p-coumaroylqunic acids (3-, 4-, and 5-p-CoQA). Caffeoylferuloylquinic acids (CFQA) are minor CGA compounds also found in green coffee, especially in Coffea robusta species, as described in U.S. patent application Ser. No. 263292 titled Effects Of A Decaffeinated Green Coffee Extract On Body Weight Control By Regulation Of Glucose Metabolism, filed Oct. 31, 2008 on behalf of Lemaire, et al., and published on May 6, 2010 as publication number U.S. 2010/0112098 A1 (hereafter “Lemaire”), the entirety of which is incorporated herein by reference as though set forth in full herein. Very small amounts of CGA lactones formed by heating during primary processing may also be observed (Farah et al. Braz J Plant Physiol. 2006, 18:23-36.—Farah et al. J Agric Food Chem. 2005; 53:1505-13).
While green coffee beans have recently been recognized to have some potentially important health benefits (see, e.g., Lemaire, above), products created from green coffee beans have not been widely available like roasted coffee. Part of the reason for this is that processing, preserving and packaging coffee beans in their nutritious, unroasted, “green” state has been difficult, expensive and generally not feasible. For example, Lemaire teaches only extracting certain substances from the green coffee bean, not processing of the entire green coffee bean.
Accordingly, what is needed is an improved method of processing green coffee beans, including partial or whole green coffee beans, that can be used to more easily and inexpensively create green coffee bean products, such as capsules, tablets, mixes, additives, supplements, and the like. Such an improved method is needed to unlock the potential health benefits to consumers of relatively inexpensive products created with green coffee beans, especially whole green coffee beans.